Earliest available weather forecasts for October to December suggest that the northeast monsoon is likely to be normal or just below normal.

The International Research Institute (IRI) for Climate and Society at Columbia University rules out scope for any `spectacular' show either over south peninsular India or the southeast coast.

Seasonal outlook published by the IRI, on Friday, said that October-November-December may see excess showers only over the extreme southern tip of the peninsula (southern Tamil Nadu and adjoining south Kerala).

NO DEVIATION

There is no marked deviation seen from the normal for northwest India and the rest of the country except over Rajasthan where dry climate is indicated.

But mercury levels are forecast above normal for the northwest and central India, which may not benefit the Rabi crop.

November-December-January is likely to see below normal rains over the peninsula except southeast Tamil Nadu and the coast along east-central India. The rest of the country is tipped to see `climatology' features dominate (no marked deviation from the normal).

Mercury levels are forecast to stay slightly high over much of the country except eastern India.

Meanwhile, India Meteorological Department (IMD) said that the monsoon has been active over sub-Himalayan West Bengal, Sikkim and south interior Karnataka during the 24 hours ending Friday morning.

Isolated heavy rainfall has been forecast for sub-Himalayan West Bengal, Sikkim, the northeast States and Kerala during the next two days.

Scattered to fairly widespread rainfall has been forecast over parts of south peninsular India.

ACTIVE MONSOON

The Chennai Met Centre said in its update that the monsoon has been active over south interior Karnataka.

Rainfall occurred at many places over Kerala and south interior Karnataka and at a few places over Tamil Nadu, Rayalaseema, Lakshadweep and coastal and north interior Karnataka.

Isolated rainfall occurred over coastal Andhra Pradesh and Telangana.

Forecast for the next two days said that rain or thundershowers are likely at many places over interior Tamil Nadu, coastal and south interior Karnataka, Kerala and Lakshadweep; and at a few places over coastal Tamil Nadu, Puducherry and Rayalaseema.

Isolated rain or thundershowers are likely over north interior Karnataka, Telangana and coastal Andhra Pradesh.

A warning valid for the period said that isolated heavy rain is likely over interior Tamil Nadu, coastal and south interior Karnataka, Kerala and Lakshadweep during the next two days.

TROUGH PERSISTS

Meanwhile, the north-south trough running down from sub-Himalayan West Bengal to southwest Bay of Bengal persisted.

The trough also featured two upper air cyclonic circulations over west-central Bay of Bengal and southwest Bay of Bengal.

Satellite pictures, on Friday, showed convective clouds over parts of southeast Arabian Sea, west-central and south Bay of Bengal, south Andaman Sea and the northeastern States.

The European Centre for Medium-Range Weather Forecasts (ECMWF) has said in its outlook that south peninsular India would continue to see unsettled weather activity even beyond September 30 when the monsoon is expected to pass.

An active trough of low-pressure (not measuring up to a low-pressure area) is forecast to persist over southwest and west-central Bay of Bengal during this period, the ECMWF said in its forecasts